Joy stick support structure for multidirectional switch

Abstract: A multi-directional switch (1) comprises a joy stick (6) which is inclined for selective operation of a plurality of switch portions. The joy stick (6) includes a support potion (6a) supported pivotally about the bottom end thereof; a slidable contact spherical portion (6b) bulging from the top end of the support portion (6a) and having a spherical surface (6e) slidably abutting throughout the circumference thereof against the inner peripheral surface of a through hole (5a) when pivoted; and an operating portion (6c) projecting through the through hole (5a) adjacent the spherical surface (6e). The outer periphery of a flat surface (6d) of the slidable contact spherical portion (6b) of the joy stick (6) is supported at four circumferentially spaced positions so that the joy stick (6) is returned to a neutral position by the elastic restoring force of the switch portions. A joy stick support structure for the multi-directional switch (1) requires neither a particularly part for returning the joy stick (6) to the neutral position nor a securely determined fulcrum.

Description: The present invention relates to a joy stick support structure for a multi-directional switch for selectively controlling a plurality of switch portions. Description of the Prior Art This type of multi-directional switch is disclosed in Japanese Utility Model Application Laid-Open No. 57-128731 (1982) and Japanese Utility Model Application Laid-Open No. 1-111431 (1989), for example. The prior art multi-directional switch includes four switch portions formed on a printed wiring board or the like, a joy stick supported pivotally about a pivot fulcrum located centrally of the four switch portions, and a spring element such as a coil spring and a plate spring for returning the joy stick to its neutral position. An operating portion of the joy stick which projects from a through hole of a panel is inclined against the elastic force of the spring element, to incline the joy stick. One of the switch portions is selectively turned into the on position by the joy stick, depending on the direction of the inclination. When the operating force exerted upon the joy stick is released, the elastic force accumulated in the spring element forces the joy stick to return to the neutral position, and the one switch portion is returned to the off position by the restoring force thereof. The above-mentioned prior art multi-directional switch structure, however, is of the type wherein the joy stick is returned to the neutral position by the spring element such as a coil spring and a plate spring. In this structure, it is necessary to securely determine the pivot fulcrum of the joy stick so that the joy stick is returned to the neutral position spaced from the switch portions, resulting in an increased number of parts and deterioration in productivity. Further, an additional spring element such as a coil spring and a plate spring is required to return the joy stick to the neutral position, which results in an increased number of parts and the increased total size of the structure. US-A-4408103 discloses a joy stick support structure according to the preambles of claims 1 and 8, having a plurality of contact regions and corresponding conductive regions mounted on a piece of resilient material resting on the surface, with each conductive region contained within a hollowed portion of the resilient material to be thereby spaced apart from the respective contact region, and having a swivelingly mounted joystick. SUMMARY OF THE INVENTION The present invention is intended for a joy stick support structure for a multi-directional switch, the multi-directional switch including a plurality of switch portions released and restored by an elastic restoring force, a joy stick having an operating portion and supported returnably to a neutral position, the joy stick being inclined by the operating portion to selectively operate the plurality of switch portions, and a cover panel for covering the switch portions and having a through hole through which the operating portion projects. According to the present invention, the joy stick comprises a support portion supported pivotally about one end thereof adjacent the switch portions of the multi-directional switch, a slidable contact spherical portion bulging from the other end of the support portion and having a spherical surface slidably abutting throughout the entire circumference thereof against an inner peripheral surface of the through hole when pivoted, the operating portion projecting from the spherical surface. An outer periphery of the slidable contact spherical portion adjacent the support portion is supported in at least three circumferentially spaced positions so that the joy stick is returned to the neutral position by the elastic restoring force of the switch portions. According to the present invention, when the operating portion of the joy stick projecting through the through hole of the cover panel is pressed in a predetermined direction, the joy stick is inclined about one end of the support portion. The inclination of the joy stick permits the slidable contact spherical portion to selectively switch on a desired switch portion. When the operating force exerted upon the joy stick is released, the slidable contact spherical portion is pressed back by the elastic restoring force of the switch portion which is on, and the joy stick is then returned to the neutral position and the switch portion is switched off. Thus, there is no need to provide an additional member for returning the joy stick to the neutral position, thereby permitting reduction in the number of parts and facilitating the structure. This provides for cost reduction, space reduction, and improvement in productivity. Further, the through hole of the cover panel is constantly covered with the spherical surface of the slidable contact spherical portion slidably abutting thereagainst during the inclination of the joy stick, requiring no parts for concealing the interior of the switch and effectively preventing dust from entering the interior of the switch. In another aspect of the present invention, the cover panel comprises at least three point contact support projections formed in circumferentially spaced relation on an inner peripheral surface of the through hole. The joy stick comprises a support portion supported pivotally about one end thereof adjacent the switch portions of the multi-directional switch, a slidable contact spherical portion bulging from the other end of the support portion and having a spherical surface in point contact with the point contact support projections, the spherical surface being slidable in point contact with the point contact support projections when pivoted, the operating portion projecting from the spherical surface. An outer periphery of the slidable contact spherical portion adjacent the support portion is supported in at least three circumferentially spaced positions so that the joy stick is returned to the neutral position by the elastic restoring force of the switch portions. The slidable contact spherical portion of the joy stick slides in point contact with the point contact support projections formed on the inner peripheral surface of the through hole of the cover panel during the inclination of the joy stick. Thus, the frictional resistance is very small at the contact between the joy stick and the cover panel, and the joy stick is smoothly inclined, thereby providing a good operating feeling. It is a primary object of the present invention to provide a joy stick support structure for a multi-directional switch which requires neither a particular part for returning a joy stick to its neutral position nor a securely determined fulcrum of the joy stick. It is another object of the present invention to provide a joy stick support structure for a multi-directional switch which provides a good operating feeling. These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of principal parts of a first preferred embodiment according to the present invention; Fig. 2 is a plan view of the principal parts of the first preferred embodiment, with a cover panel omitted; Fig. 3 is a sectional view of principal parts of the cover panel of the first preferred embodiment; Fig. 4 is a view taken in the direction of the arrows IV-IV of Fig. 3; Fig. 5 is a sectional view of principal parts of a second preferred embodiment according to the present invention; Fig. 6 is a sectional view of principal parts of the cover panel of the second preferred embodiment; and Fig. 7 is a view taken in the direction of the arrows VII-VII of Fig. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS A first preferred embodiment according to the present invention will now be described hereinafter, with reference to the drawings. As shown in Figs. 1 and 2, a multi-directional switch 1 comprises a printed wiring board 2 having a suitably formed wiring pattern, a rubber contact switch sheet 3 made of a rubber material or the like and including elastically deformable contact switch portions 3a, a guide plate 4, a cover panel 5, and a joy stick 6. The elements 4, 5 and 6 are made of a synthetic resin or the like. The rubber contract switch sheet 3 includes the four bulging contact switch portions 3a constantly spaced in a circumferential direction of a circle having a desired diameter. As shown in Fig. 1, the rubber contact switch sheet 3 is superposed upon the printed wiring board 2 so that the contact switch portions 3a project upwardly. Contacts 2a of the printed wiring board 2 and contacts 3b of the contact switch portions 3a are opposed to each other in vertically suitably spaced relation. The respective contacts 2a and 3b form a plurality of freely connectable/disconnectable switch portions. The guide plate 4 is superposed upon the rubber contact switch sheet 3, as shown in Fig. 1. Vertical circular recesses 4a are formed in a lower surface of the guide plate 4 in corresponding relation to the contact switch portions 3a to house the contact switches 3a, respectively. The guide plate 4 further includes vertical guide holes 4b formed therethrough at the center of the bottom of the respective circular recesses 4a. Cooperating rods 8 each includes a disc portion 8a vertically slidably guided along the inner peripheral surface of the corresponding circular recess 4a, and a guide rod 8b vertically slidably guided along the inner peripheral surface of the corresponding guide hole 4b. The disc portions 8a are disposed on the upper surface of the contact switch portions 3a, and the guide rods 8b project upwardly from the guide holes 4b, respectively. Each of the guide rods 8b of the cooperating rods 8 has a hemispherical top end. The guide plate 4 further includes a fulcrum recess 4c in the upper surface thereof at the center of the circular recesses 4a. The joy stick 6 includes a support portion 6a, a slidable contact spherical portion 6b, and an operating portion 6c, which are disposed coaxially in this order, as shown in Fig. 1. The bottom end of the support portion 6a is received in the fulcrum recess 4c of the guide plate 4 serving as a body, and the joy stick 6 is supported pivotally about the received bottom end of the support portion 6a. The slidable contact spherical portion 6b bulges from the top end of the support portion 6a. The lower end surface of the slidable contact spherical portion 6b includes a flat surface 6d perpendicular to the axis of the support portion 6a and is of circular configuration about the axis of the support portion 6a. The upper surface of the slidable contact spherical portion 6b includes a spherical surface 6e centered on the pivot center at the bottom end of the support portion 6a. Thus, the slidable contact spherical portion 6b is of a so-called hemispherical configuration. The outer periphery of the flat surface 6d is urged upwardly and supported at circumferentially equally spaced positions by the elastic restoring force of the contact switch portions 3a from the top ends of the guide rods 8 of the cooperating rods 8. The spherical surface 6e slidably abuts throughout the entire circumference thereof against a circumferentially continuous, circular ledge 5b formed on the inner peripheral surface of a circular through hole 5a of the cover panel 5, as shown in Figs. 3 and 4. The operating portion 6c at the center of the spherical surface 6e projects upwardly through the through hole 5a of the cover panel 5 for covering the guide plate 4, the cooperating rods 8, and the joy stick 6. In the above-stated first preferred embodiment of the present invention, the joy stick 6 is adapted such that the outer periphery of the flat surface 6d is urged upwardly at the circumferentially equally spaced positions by the elastic restoring force of the contact switch portions 3a through the cooperating rods 8, and the spherical surface 6e of the joy stick 6 abuts against the ledge 5b of the cover panel 5 by the urging force, thereby effectively preventing the joy stick 6 from being unsteady. As shown in phantom in Fig. 1, when the operating portion 6c of the joy stick 6 is pushed leftwardly, the joy stick 6 is inclined about the bottom end of the support portion 6a serving as the fulcrum. During the inclination of the joy stick 6, the support recess 4c receives and supports the bottom end of the support portion 6a of the joy stick 6. The structure of the first preferred embodiment is of the type wherein the joy stick 6 is inclined under the urging force of at least one of the contact switch portions 3a. The spherical surface 6e of the slidable contact spherical portion 6b constantly slides along the ledge 5b of the cover panel 5. This provides a stable operating feeling without a securely determined fulcrum. The inclination of the joy stick 6 causes the outer periphery of the flat surface 6d of the slidable contact spherical portion 6b to press one of the cooperating rods 8 downwardly under guidance of the corresponding guide hole 4b. Then the corresponding contact switch portion 3a is pressed downwardly against the elastic force thereof by the corresponding disc portion 8a of the operating rod 8, and the corresponding contacts 2a and 3b come in contact with each other into the on position. When the operating force exerted upon the joy stick 6 is released, the elastic restoring force of the contact switch portion 3a which is on forces the corresponding cooperating rod 8 upwardly, which in turn causes the corresponding guide rod 8b of the cooperating rod 8 to press back the slidable contact spherical portion 6b. Then the joy stick 6 is returned to the initial neutral position, and the corresponding contacts 2a and 3b are separated from each other to return the corresponding contact switch portion 3a to the off position. As above described, since the structure of the first preferred embodiment is of the type wherein the joy stick 6 is returned to the neutral position by the elastic restoring force of the respective contact switch portions 3a, there is no need to provide an additional member for returning the joy stick 6 to the neutral position such as the prior art coil spring or plate spring. Further, it is unnecessary to securely determine the fulcrum of the joy stick 6, which provides for reduction in the number of parts and, accordingly, facilitates the structure. This permits cost reduction, space reduction, and improvement in productivity. Further, the spherical surface 6e of the slidable contact spherical portion 6b of the joy stick 6 constantly covers the through hole 5a of the cover panel 5 in a closing manner during the inclination of the joy stick 6. This structure requires no parts for concealing the interior of the multi-directional switch 1 and effectively prevents dust from entering the interior of the multi-directional switch 1. Although the structure includes the four switch portions in the first preferred embodiment, three or five switch portions may be provided, and the number of switch portions is not limited to that of the first preferred embodiment. The structure of the switch portions is not limited to that of the first preferred embodiment, and various types of switch portions are applicable which are automatically restored by the elastic restoring force. Although the single switch portion is operated by the inclination of the joy stick 6 in the first preferred embodiment, a plurality of switch portions may be simultaneously operated. Referring to Figs. 5 to 7, a second preferred embodiment will be discussed hereinafter according to the present invention. Like reference numerals and characters are used to designate parts identical with those of the first preferred embodiment, and the description thereof will be omitted herein. Similar to the first preferred embodiment, the joy stick 6 is adapted such that the outer periphery of the flat surface 6d is supported and urged upwardly at circumferentially equally spaced positions by the elastic restoring force of the contact switch portions 3a from the top ends of the guide rods 8b of the cooperating rods 8. The spherical surface 6e is in point contact with and relatively slidably supported by four point contact support projections 5c formed in circumferentially equally spaced relation on the inner peripheral surface of the circular through hole 5a of the cover panel 5. In the above-stated second preferred embodiment of the present invention, similar to the first preferred embodiment, the joy stick 6 is adapted such that the outer periphery of the flat surface 6d is urged upwardly at the circumferentially equally spaced positions by the elastic restoring force of the contact switch portions 3a through the respective cooperating rods 8, and the spherical surface 6e of the joy stick 6 abuts against the respective point contact support projections 5c by the urging force, thereby effectively preventing the joy stick 6 from being unsteady. As shown in phantom in Fig. 5, when the operating portion 6c of the joy stick 6 is pushed leftwardly, the joy stick 6 is inclined about the bottom end of the support portion 6a serving as the fulcrum. During the inclination of the joy stick 6, the fulcrum recess 4c receives and supports the bottom end of the support portion 6a of the joy stick 6. The structure of the second preferred embodiment is of the type wherein the joy stick 6 is inclined under the urging force of at least one of the contact switch portions 3a. The spherical surface 6e of the slidable contact spherical portion 6b constantly slides in point contact with the respective point contact support projections 5c of the cover panel 5. This provides a stable operating feeling without the securely determined fulcrum. The inclination of the joy stick 6 causes the outer periphery of the flat surface 6d of the slidable contact spherical portion 6b to press one of the cooperating rod 8 downwardly under guidance of the corresponding guide hole 4b. Then the corresponding contact switch portion 3a is forced downwardly against the elastic force thereof by the corresponding disc portion 8a of the cooperating rod 8, and the corresponding contacts 2a and 3b come in contact with each other into the on position. When the operating force exerted upon the joy stick 6 is released, the elastic restoring force of the contact switch portion 3a which is on forces the corresponding cooperating rod 8 upwardly, which in turn causes the corresponding guide rod 8b of the cooperating rod 8 to press back the slidable contact spherical portion 6b. Then the joy stick 6 is returned to the initial neutral position, and the corresponding contacts 2a and 3b are separated from each other to return the corresponding contact switch portion 3a to the off position. As above discussed, since the structure of the second preferred embodiment is of the type wherein the joy stick 6 is returned to the neutral position by the elastic restoring force of the respective contact switch portions 3a, there is no need to provide an additional member for returning the joy stick 6 to the neutral position such as the prior art coil spring or plate spring. Furthermore, it is unnecessary to securely determine the fulcrum of the joy stick 6, which provides for reduction in the number of parts and, accordingly, facilitate the structure. This permits cost reduction, space reduction, and improvement in productivity. On the other hand, since the spherical surface 6e of the slidable contact spherical portion 6b slides in point contact with the respective point contact support projections 5c during the inclination of the joy stick 6, a frictional resistance is very small at the contact between the joy stick 6 and the cover panel 5. This provides smooth inclination of the joy stick 6 and a good operating feeling. The second preferred embodiment is less influenced by dust or powders made due to abrasion but provides a constantly stable, good operating feeling. Although the structure includes the four switch portions in the second preferred embodiment, three or five switch portions may be provided, and the number of switch portions is not limited to that of the second preferred embodiment. Although the structure includes the four point contact support projections 5c in the second preferred embodiment, three or five point contact support projections may be provided, and the number of point contact support projections is not limited to that of the second preferred embodiment. The structure of the switch portions is not limited to that of the second preferred embodiment, and various types of switch portions are applicable which are automatically restored by the elastic restoring force. Although the single switch portion is operated by the inclination of the joy stick 6 in the second preferred embodiment, a plurality of switch portions may be simultaneously operated. While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised within the scope of the invention as defined in the claims.

Claims: A joy stick support structure for a multi-directional switch (1), said multi-directional switch including a plurality of switch portions (2a,3b) released and restored by an elastic restoring force, a joy stick (6) having an operating portion (6c) and supported returnably to a neutral position, said joy stick (6) being inclined by said operating portion (6c) to selectively operate said plurality of switch portions (2a,3b), and a cover panel (5) for covering said switch portions (2a,3b) and having a through hole (5a) through which said operating portion (6c) projects, said joy stick comprising a support portion (6a) supported pivotally about one end thereof adjacent said switch portions (2a,3b) of said multi-directional switch (1), a slidable contact spherical portion (6b) bulging from the other end of said support portion (6a) and having a spherical surface (6e) slidably abutting throughout the entire circumference thereof against an inner peripheral surface of said through hole (5a) when pivoted, said operating portion (6c) projecting from said spherical surface (6e), characterized in that said slidable contact spherical portion (6b) is of a hemispherical configuration, wherein an outer periphery of the flat lower end surface (6d) of said slidable contact spherical portion (6b) adjacent said support portion (6a) is supported in at least three circumferentially spaced positions so that said joy stick (6) is returned to the neutral position by the elastic restoring force of said switch portions (2a,3b). The joy stick support structure of claim 1, wherein said cover panel (5) includes a ledge (5b) formed on the inner peripheral surface of said through hole (5a) and extending circumferentially throughout, and said spherical surface (6e) slidably abuts against said ledge (5b). The joy stick support structure of claim 1, wherein said plurality of switch portions (2a,3b) are constantly spaced in a circumferential direction of a circle having a desired diameter. The joy stick support structure of claim 3, wherein said cover panel (5) includes a ledge (5b) formed on the inner peripheral surface of said through hole (5a) and extending circumferentially throughout, and said spherical surface (6e) slidably abuts against said ledge (5b). The joy stick support structure of claim 4, wherein said multi-directional switch (1) includes a printed wiring board (2) having a plurality of first contacts (2a), and a contact switch sheet (3) superposed upon said printed wiring board (2) and having a plurality of elastically deformable, bulging contact switch portions (3a) having second contacts (3b) opposing said first contacts (2a), respectively, and wherein said opposed first and second contacts (2a,3b) form said switch portions, respectively. The joy stick support structure of claim 5, wherein said multi-directional switch (1) further includes a guide plate (4) superposed upon said contact switch sheet (3) superposed upon said printed wiring board (2), and said guide plate (4) includes circular recesses (4a) receiving the corresponding contact switch portions (2a,3b), respectively, and guide holes (4b) extending through said guide plate (4) on the bottom of said circular recesses (4a), respectively, wherein said multi-directional switch (1) further includes cooperating rods (8) having disc portions (8a) slidably guided along an inner peripheral surface of the corresponding circular recesses (4a), and guide rods (8b) slidably guided along an inner peripheral surface of the corresponding guide holes (4b), respectively, and wherein the outer periphery of the flat lower end surface (6d) of said slidable contact spherical portion (6b) adjacent said support portion (6a) is supported by projecting ends of said guide rods (8b) of said cooperating rods (8) urged by the elastic restoring force of said contact switch portions (2a,3b). The joy stick support structure of claim 6, wherein said guide plate (4) includes a fulcrum recess (4c) formed centrally of said switch portions (2a,3b) in a surface thereof opposite to said contact switch sheet (3) for pivotally supporting said support portion (6a). A joy stick support structure for a multi-directional switch (1), said multi-directional switch including a plurality of switch portions (2a,3b) released and restored by an elastic restoring force, a joy stick (6) having an operating portion (6c) and supported returnably to a neutral position, said joy stick (6) being inclined by said operating portion (6c) to selectively operate said plurality of switch portions (2a,3b), and a cover panel (5) for covering said switch portions (2a,3b) and having a through hole (5a) through which said operating portion (6c) projects, said joy stick comprising a support portion (6a) supported pivotally about one end thereof adjacent said switch portions (2a,3b) of said multi-directional switch (1), a slidable contact spherical portion (6b) bulging from the other end of said support portion (6a) and having a spherical surface (6e), said operating portion (6c) projecting from said spherical surface (6e), characterized in that said cover panel (5) comprises at least three point contact support projections (5c) formed in circumferentially spaced relation on an inner peripheral surface of said through hole (5a), said spherical surface (6e) is in point contact with said point contact support projections (5c), said spherical surface (6e) being slidable in point contact with said point contact support projections (5c) when pivoted, and said slidable contact spherical portion (6b) is of a hemispherical configuration, wherein an outer periphery of the flat lower end surface (6d) of said slidable contact spherical portion (6b) adjacent said support portion (6a) is supported in at least three circumferentially spaced positions so that the joy stick (6) is returned to the neutral position by the elastic restoring force of said switch portions (2a,3b). The joy stick support structure of claim 8, wherein said plurality of switch portions (2a,3b) are constantly spaced in a circumferential direction of a circle having a desired diameter. The joy stick support structure of claim 9, wherein said multi-directional switch (1) includes a printed wiring board (2) having a plurality of first contacts (2a), and a contact switch sheet (3) superposed upon said printed wiring board (2) and having a plurality of elastically deformable, bulging contact switch portions (3a) having second contacts (3b) opposing said first contacts (2a), respectively, and wherein said opposed first and second contacts (2a,3b) form said switch portions, respectively. The joy stick support structure of claim 10, wherein said multi-directional switch (1) further includes a guide plate (4) superposed upon said contact switch sheet (3) superposed upon said printed wiring board (2), and said guide plate (4) includes circular recesses (4a) receiving the corresponding contact switch portions (2a,3b), respectively, and guide holes (4b) extending through said guide plate (4) on the bottom of said circular recesses (4a), respectively, wherein said multi-directional switch (1) further includes cooperating rods (8) having disc portions (8a) slidably guided along an inner peripheral surface of the corresponding circular recesses (4a), and guide rods (8b) slidably guided along an inner peripheral surface of the corresponding guide holes (4b), respectively, and wherein the outer periphery of the flat lower end surface (6d) of said slidable contact spherical portion (6b) adjacent said support portion (6a) is supported by projecting ends of said guide rods (8b) of said cooperating rods (8) urged by the elastic restoring force of said contact switch portions (2a,3b). The joy stick support structure of claim 11, wherein said guide plate (4) includes a fulcrum recess (4c) formed centrally of said switch portions (2a,3b) in a surface thereof opposite to said contact switch sheet (3) for pivotally supporting said support portion (6a).

Inventors: KOJIMA JUNICHI, NAITOU KIYOTAKA, KOJIMA, JUNICHI, NAITOU, KIYOTAKA, KOJIMA, JUNICHI, C/O SUMITOMO WIRING SYSTEMS, LTD, NAITOU, KIYOTAKA, C/O SUMITOMO WIRING SYSTEMS, LTD
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01H25
IPC codes: G05G9